Have you any other gas appliances like say a cooker.Is a similar thing happening there as it could be a faulty filter and governor at the gas meter.British Gas Transco will pay a free visit to check it out for you if you mention possible pressure problems.
Tony S
February 2009
i would be very careful with this boiler as they are positively fanned which means any defect in the case seals,corrosion to the backpanel etc will result into fumes entering the room. I would definatley buy an alarm type carbon monoxide detector and get the boiler checked but if its is corrosion problem you will need to replace it.